Any person engaged in the practice or teaching of geological science may apply for Active membership, provided the applicant holds a degree in geological science from an acceptable college. The degree requirement may be waived by the Board of Directors if the applicant has adequate geological experience.

A corporate member may be any corporation or organization whose activities and/or interests, at least in part, concern the science of geology and the advancement of geological study within their industry and community. The member will be awarded two (2) designated representatives, both of which must qualify as Active members established under the By-laws of the Society and both shall be in the employ of the company. The two (2) designated representatives of the corporation shall be exempt from paying individual dues but will have all rights established for individual Active members under Article III, Section 1A. The corporation shall have no voting rights. Membership eligibility, dues and certain rights and privileges of the corporate members require a majority vote of the Board of Directors.

Emeritus members may be any member who has reached the age of 70 years old and has been a member of the South Texas Geological Society for a minimum of ten years, cumulative. The dues amount for such a membership will be set by the Board of Directors and be a one-time membership fee payable upon approval, rather than an annual membership fee option. (They will remain an Active member and are eligible for all the privileges of that classification.)